Method of applying internal metallic linings to tubes and the like



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Aug. 27, 1963 grip.

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United States Patent() 3,191,531 METHD UF APPLYING INTERNAL METALLIC LINWGS T TUBES AND THE LIKE Thomas J. Roseherry, Anaheim, Calif., assigner to Western Gear Corporation, Lynn/ood, Calif., a corporation of California 4Filed Jan. 9,1961, Ser. No. 81,485 3 Claims. (Cl. 29-l7t.4)

-T his invention relates generally to internally lined tubes and has as its general object to provide a new and unique process tor lining tubes internally.

-Another object of the inevntion is to provide a process of the character described wherein the liner material is fusion bonded to the lined tube.

Yet another object ofthe invention is to provide a process of the character described which is especially adapted to lining tubes with metals having relatively high melting points.

A turther object of the inevntion is to provide a process of the character described which is extremely simple and economical and provides a superior end product.

Other objects, advantages and tfeatures of the invention will become readily evident as the description proceeds.

The invention will now be described in detail by referi ence to the attached drawing wherein:

FIG. 1 diagrammatically illustrates the present process; and

FIG. 2 is an enlarged, longitudinal section through a tube which has been internally lined by the present process.

Referring 'first to FIG. l of the drawing, the first step of the present process involves the preparation of a mandrel .10. This mandrel is machined or other-Wise provided with an outside diameter which is slightly less than the desired tinal inside diameter of the tube 12 to be lined. i

'Ilhe next step of the process involves coating the mandrel with the material .14 with which the tube 12 is to be lined. As was preliminarily noted, and as will become apparent as the description proceeds, the present process is especially adapted der lining tubes with metals having relatively high melting points. 'Ilhe liner material 14 may be applied to the mandrel in various well-known Ways, such as rby a high temperature spray technique as diagrammatically illustrated in the drawing.

The third step of the process involves applying la layer of fushiombonding material 16 to the coated mandrel resulting from step nwo. Various types lof tushion bond materials are known which may -be used in the present process, such as copper, silver alloys, and chrome-nickelboron alloy. Ilhe bonding material may be :applied in any convenient Way, such as .by a spray technique, plating or manually.

The bonding material is now I:fused to the 'liner material 14 on the mandrel. This may be accomplished in a controlled atmosphere furnace 1S, tor example, or otherwise by an oxyacetylene torch or any yother suitable means.

rDhe coated and fused mandrel emerging from the turna-ce is ground or 'otherwise machined to an outside diameter Winch Will afford on the order of a .001 inch interference press lit of the coated mandrel in the tube i12 "ice . 2 ing this step, then, the liner material 14 acquires a -fusion bond to the tube 12.

Final step eight of the process involves removal of the mandrel 410 trom the assembly. 'llhis may be accomplished in various Ways, such :as by 1a boring operation as illustrated. The tube 10 with its fusion bonded liner 14 remains, as illustrated in FIG. 2, and forms the final product of the process.

It is obvious, there-fore, that the process herein described and illustrated is fully capable of attaining the several objects and advantages set torth.

What is claimed is: l. 'Ilhe method Iof lining la tube, which comprises the steps of:

preparing a cylindrical mandrel having fan external diameter less than the internal diameter or the tube,

coating said mandrel a layer of a metallic lining material having yan external diameter slightly less than the internal diameter of the tube, coating said layer of lining material with a layer ot fusion Ibouding material having an external diameter slightly greater than the internal diameter of the tube,

hearing the coated mandrel to a temperature sufficient to fuse said layer of lusion bonding material to said layer of metallic lining material,

machining the coated mandrel to `afford the latter with a friction tit in said tube,

press litting the machined, coated mandrel into the tube,

heating the tube 'and coated mandrel therein to fuse said layer of fusion bonding materia-l to the inner iwall tot the tube, and

removing said mandrel from the tube by passing a rotary, metal cutting tool having a diameter less than the external diameter of said layer ot lining material axially through the tube.

2. The method of lining a tube, which comprises the steps of: preparing a cylindrical mandrel having an external diameter lessA than the internal diameter of the tube,

coating said mandrel with Ia layer of `a metallic lining material having an external diameter slightly less than the internal diameter of the tube,

coating said layer ol lining material with a layer of metallic tusion bonding material having `an external diameter slightly greater than the internal diameter ot the tube,

heating the coated mandrel to la temperature suicient to `fuse said layer of metallic tusion bonding material to said |layer of metallic lining material, machining' the coated mandrel to alford the latter `With a friction t in said tube, press iitting the machined, coated mandrel into the tube, heating the tube and coated mandrel therein to fuse said layer 'ot metallic fusion bonding material to the inner Wall of the tube, and

removing said mandrel trom the tube by passing a rotary, metal cutting tool having a diameter less than the external diameter of said layer of lining material axially through the tube.

3. The method of lining a tube, which comprises the steps of:

preparing a cylindrical mandrel having an |euternal I :diameter less than the internal diameter of the tube,

. spraying sa molten metallic lining mate-rial on said mandrel to provide the latter with a layer of said lining material havingl an outside diameter slightly less than the internal diameter of the tube,

l spraying a molten metallic tusion bonding material over said layer ot metallic lining material to provide the mandrel with a layer of metallic fusion bonding material having an ioutside diameter greater than the internal diameter of the tube,

heating the coated mandrel to =a temperature sulicient to fuse said Mayer tof metallic fusion bonding matenial to said layer 'of metallic lining material,

machining the coated mandrel to afol'd the latter with 'a @fiction fit in said tube,

press litting the machined, coated mandrel into the tube,

heating the tube land coated mandrel therein toy fuse said layer tof metallic Ifusion bonding material to the inner Wall rof the tube, and

il removing said mandrel trom the tube by passing a notary, metal cutting tool having 'a diameter less than the external diameter of said layer of lining material axially through the tube.

References Cited in the file of this patent UNITED STATES PATENTS 642,539 Thoma lJan. 30, 1900 1,745,483 Hansen Feb. 4, 1930 2,074,007 Wissler Mar. 16, 1937 2,768,921 Pilgg Oct. 30, 1956 

1. THE METHOD OF LINING A TUBE, WHICH COMPRISES THE STEPS OF: PREPARING A CYLINDRICAL MANDREL HAVING AN EXTERNAL DIAMETER LESS THAN THE INTERNAL DIAMETER OF THE TUBE, COATING SAID MANDREL WITH A LAYER OF A METALLIC LINING MATERIAL HAVING AN EXTERNAL DIAMETER SLIGHTLY LESS THAN THE INTERNAL DIAMETER OF THE TUBE, COATING SAID LAYER OF LINING MATERIAL WITH A LAYER OF FUSION BONDING MATERIAL HAVING AN EXTERNAL DIAMETER SLIGHTLY GREATER THAN THE INTERNAL DIAMETER OF THE TUBE, HEATING THE COATED MANDREL TO A TEMPERATURE SUFFICIENT TO FUSE SAID LAYER OF FUSHION BONDING MATERIAL TO SAID LAYER OF METALLIC LINING MATERIAL, 